Pyroxylin solvent and composition contaiitingt



untrue sitar-Es Parana curios.

EDMUND M. FLAHERTY, OE PARLIN, NEW JERSEY, nssrcuvoia T0 E. I. DU Pom.DE

ivEMoUEs AND COMPANY, OE WILMINGTON, DELAWARE, a CORPORATION orDELAWARE.

IPYB.OXYLIN SOLVENT Arm coiurosrrloiv coivrlaimivernn SAME.

11,323,624l; No Drawing. Application filedmfareh '5, 1918,

To all whom it may concern:

Be itknown that I, EDMUND M. FLAHERTY, of Parlimin the county ofMiddlesex, and in the State of New Jersey, have invented a certain newand useful Improvement in Pyroxylin Solvent and Compositions Containingthe Same, and'do hereby declare that the following is'a full, clear, andexact description thereof.

The object of my invention is to provide a solvent for pyroxylin bodieshaving the qualities of being cheap, having high. solvent power,beingfree from precipitation of li non-hygro copic, adapted to form avery fluid. but cohesive solution, and of pleasant odor.

A furtherobjectis to use a solvent composition containing constituentswhich have approximately the same vapor tension, as it is desirable tohave a number of the constituents evaporate more or less simultaneously.

A'further object is to provide a solvent composition which, by reason ofthe presence of the particular alcohol therein, can be regulated as toits fluidity by varying the quantity of the alcohol as compared with thequantity of solid constituents therein.

In the pyroxylin industries, such as in the manufacture of lacquers,artificial leather, varnishes, etc, there is a demand for a solventhaving the above-stated qualities.

None of the ordinary pyroxylin solvents, such as glacial acetic acid,amyl acetate and acetone, including their homologues and-derivatives,has all of these properties in the highest degree, except,.perhaps, amylacetate,.the price of which is very high. In

these several industries, it is desirable tovary the relativeproportions of'the solvent and pyroxylin to obtain a solution of thestrength desired, accordmg to the nature of the yroxylin film-to beormed. For. examp e, in lacquer work the solution ordinarily does notcontain over five ounces of pyroxylin per gallon in order that a film ofproper thickness may be deposited. In.

some of the decorative arts a very heavy film is. employed, which can bedeposited from a solution containing as high as twenty ounces ofpyroxylin per gallon. There is, thus for each industry a strength ofsolution which Specification of Letters latent.

Patented Dec. 2, 1919..

Serial No. 220,487. Renewed September 26, 1919. Serial No. 326,537.

is best adapted thereto. Where a solution is desired having less'pyroxylin than the total amount which the solvent is'capable of takmgup (for instance, if a solution of twenty ounces of pyroxylin to agallon of solvent. were desired, which is less than the total amountwhich the solvent would take up), 1t is unnecessary to have the entirequantity ofsolution composed of pure solvent, it only being necessary tohave enough solvent present. to dissolve the-desired amount of pyroxylm.For economy, therefore, it is customary to'add cheap diluents to thesolvent, which diluents are either entirely non-solvent or nearly so.The use of diluents,l1.owever, introduces diiliculties, among whichmaybe mentioned the following: When, as used in a factory,these solventsare evaporated at the ordinary room atmosphere in order to deposit afilm of pyroxylin, there is a tendency,'except in the case of thosesolvents which are non-hygroscopic but expensive, such as amyl acetate,toward a separation out of the nitrocellulose or other solvents throughabsorption of moisture from the air or through the change in thecomposition of the solvent mixture resulting from the unequal rate ofevaporation of its components, this precipitation being usuallyevidenced by the appearance of a whitish substance, technically known asblushing or blooming, or by the settling to the bottom of a jellylikemass. Such separation tends to decrease the strength of the film, and,in some cases, the white appearance produces objectionable colorefi'ects.

l havediscovered that by using a mixture of butyl acetate and xylo,l,-orone of its homologues, or solvent naphtha, with or without the presenceof an alcohol, such for example as butyl alcohol, in which compositionxylol is the diluent,- a mixture is obtained which has a maximum solventpower and is free from precipitation of the pyroxylin. Such mixture salsocomparatively non-hygroscopic. When these materials are mixedtogether, the solvent power of the more active solvent, butyl acetate,is 'retained, so. that the mixture may contain as high as sevent percent., oreven more, of xylol. l find t at during evaporation underordinary factory conditions the butyl acetate ents may vary widelyaccording to the conditions covering the innumerable uses to which thesolution may be put.

I have iven specific instances merely by way of i1 ustration, and am'notto be confined to the particular proportions given, as they are to beregarded as typical only.

An increase in the xylol component results in'reduced cost and itsdisadvantage lies in" the lessrapid solvent action which such a mixturepossesses.

The fluidity can be varied by varying the quantity of the alcohol.

Numerous other substances, such as other pyroxylin solvents, oils,pigments, gums, resins, etc., may be added to the pyroxylin mixture,each having its own properties, and these properties will, of course,efi'ect the properties of the final mixture, but the general principlewill still obtain.

Among the homologues of xylol which I may use instead of the same, I maymention toluol.

for example ethyl alcohol. For any-of these compositions, furthermore,the butyl acetate offcommerce may be used, if desired, which commercialbutyl acetate contains about 10% by weight of butyl alcohol.

I find that my mixture is comparatively non-hygroscopic, which is a verydesirable quality, since the absorption of water in Also, other acyclicalcohols may be used instead of the butyl alcohol, as

. hol.

.such a solution results in a precipitation'of the pyroxylin.

without departing from the spirit of the invention.

I claim:

1. A composition comprising a mixture of butyl acetate and xylol.

2. A composition comprising a mixture plflbutyl acetate, xylol and anacyclic alco- 31A composition comprising a mixture of butyl acetate, abenzene hydrocarbon and butyl alcohol.

4. A composition comprising a mixture of butyl acetate, xylol and butylalcohol.

5. A composition comprising pyroxylin and a pyroxylin solvent comprlsinga mixture of butyl acetate and xylol.

6. composition comprising pyroxylin and a pyroxylin solvent comprising amixture of butyl acetate, xylol and 'an acyclic alcohol.

'7. A composition comprising pyroxylin and a pyroyxlin solventcomprising a mixture of butyl acetate, a benzene hydrocarbon and butylalcohol.

8. A composition comprising pyroxylin and a pyroxylin solventcom'prlsing a mixtureof utyl acetate, xylol and butyl alco- Intestimonythat I claim the foregoing I have hereunto set my hand.

A. T. DAVENPORT, E. C, Roonv.

